From 27eeaeef08a513926481c7df999f66a731243e98 Mon Sep 17 00:00:00 2001
From: Connor Skees <connor1skees@gmail.com>
Date: Mon, 16 Nov 2020 03:09:40 -0500
Subject: [PATCH] plain-css invert accepts numbers of any unit

---
 src/builtin/functions/color/hsl.rs | 47 +++++++++++++++++++-----------
 tests/color.rs                     | 42 ++++++++++++++++++++++++--
 2 files changed, 70 insertions(+), 19 deletions(-)

diff --git a/src/builtin/functions/color/hsl.rs b/src/builtin/functions/color/hsl.rs
index b97ef24..83b2543 100644
--- a/src/builtin/functions/color/hsl.rs
+++ b/src/builtin/functions/color/hsl.rs
@@ -1,5 +1,6 @@
 use super::{Builtin, GlobalFunctionMap};
 
+use codemap::Spanned;
 use num_traits::One;
 
 use crate::{
@@ -455,14 +456,18 @@ pub(crate) fn complement(mut args: CallArgs, parser: &mut Parser<'_>) -> SassRes
 
 pub(crate) fn invert(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<Value> {
     args.max_args(2)?;
-    let weight = match args.default_arg(
-        1,
-        "weight",
-        Value::Dimension(Some(Number::from(100)), Unit::Percent, true),
-    )? {
-        Value::Dimension(Some(n), u, _) => bound!(args, "weight", n, u, 0, 100) / Number::from(100),
-        Value::Dimension(None, ..) => todo!(),
-        v => {
+    let weight = match args.get(1, "weight") {
+        Some(Err(e)) => return Err(e),
+        Some(Ok(Spanned {
+            node: Value::Dimension(Some(n), u, _),
+            ..
+        })) => Some(bound!(args, "weight", n, u, 0, 100) / Number::from(100)),
+        Some(Ok(Spanned {
+            node: Value::Dimension(None, ..),
+            ..
+        })) => todo!(),
+        None => None,
+        Some(Ok(v)) => {
             return Err((
                 format!(
                     "$weight: {} is not a number.",
@@ -474,16 +479,24 @@ pub(crate) fn invert(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<
         }
     };
     match args.get_err(0, "color")? {
-        Value::Color(c) => Ok(Value::Color(Box::new(c.invert(weight)))),
-        Value::Dimension(Some(n), Unit::Percent, _) => {
-            Ok(Value::String(format!("invert({}%)", n), QuoteKind::None))
+        Value::Color(c) => Ok(Value::Color(Box::new(
+            c.invert(weight.unwrap_or(Number::one())),
+        ))),
+        Value::Dimension(Some(n), u, _) => {
+            if weight.is_some() {
+                Err((
+                    "Only one argument may be passed to the plain-CSS invert() function.",
+                    args.span(),
+                ))?;
+            }
+            Ok(Value::String(
+                format!("invert({}{})", n, u),
+                QuoteKind::None,
+            ))
+        }
+        Value::Dimension(None, u, _) => {
+            Ok(Value::String(format!("invert(NaN{})", u), QuoteKind::None))
         }
-        Value::Dimension(None, ..) => todo!(),
-        Value::Dimension(..) => Err((
-            "Only one argument may be passed to the plain-CSS invert() function.",
-            args.span(),
-        )
-            .into()),
         v => Err((
             format!("$color: {} is not a color.", v.inspect(args.span())?),
             args.span(),
diff --git a/tests/color.rs b/tests/color.rs
index 15d74cd..e2e5269 100644
--- a/tests/color.rs
+++ b/tests/color.rs
@@ -245,8 +245,46 @@ test!(
     "a {\n  color: invert(white);\n}\n",
     "a {\n  color: black;\n}\n"
 );
-test!(invert_number, "a {\n  color: invert(10%);\n}\n");
-test!(invert_number_casing, "a {\n  color: iNveRt(10%);\n}\n");
+test!(
+    plain_invert_no_unit,
+    "a {\n  color: invert(1);\n}\n",
+    "a {\n  color: invert(1);\n}\n"
+);
+test!(
+    plain_invert_unit_percent,
+    "a {\n  color: invert(10%);\n}\n",
+    "a {\n  color: invert(10%);\n}\n"
+);
+test!(
+    plain_invert_unit_deg,
+    "a {\n  color: invert(1deg);\n}\n",
+    "a {\n  color: invert(1deg);\n}\n"
+);
+test!(
+    plain_invert_negative,
+    "a {\n  color: invert(-1);\n}\n",
+    "a {\n  color: invert(-1);\n}\n"
+);
+test!(
+    plain_invert_float,
+    "a {\n  color: invert(1.5);\n}\n",
+    "a {\n  color: invert(1.5);\n}\n"
+);
+test!(
+    plain_invert_arithmetic,
+    "a {\n  color: invert(1 + 1);\n}\n",
+    "a {\n  color: invert(2);\n}\n"
+);
+test!(
+    plain_invert_nan,
+    "a {\n  color: invert((0 / 0));\n}\n",
+    "a {\n  color: invert(NaN);\n}\n"
+);
+error!(
+    plain_invert_two_args,
+    "a {\n  color: invert(1, 50%);\n}\n",
+    "Error: Only one argument may be passed to the plain-CSS invert() function."
+);
 test!(
     invert_weight_percent,
     "a {\n  color: invert(white, 20%);\n}\n",